Ordering of ferromagnetic nanoparticles in nematic liquid crystals

I. Dierking, M. Heberle, M. A. Osipov, F. Giesselmann

Research output: Contribution to journalArticle

7 Citations (Scopus)
6 Downloads (Pure)

Abstract

Dispersions of magnetic nanoparticles in a nematic liquid crystal were investigated as magnetic fields were applied in three different boundary condition geometries: (i) planar substrates and B ⊥ n, (ii) planar substrates and B / n, and (iii) homeotropic substrates and B ⊥ n. Particle chaining is observed when a magnetic field is applied, with a periodicity perpendicular to the chains. Furthermore, linear chains are observed for the magnetic field applied perpendicular to the director, while zigzag chains are formed when the magnetic field direction is parallel to the director field. This is attributed to a change from a dipolar defect configuration around dispersed nanoparticles, to a quadrupolar one, i.e. the change from satellite to Saturn-ring defects. This effect is largely independent of the sample thickness. The dynamic development of the chain length, as well as their two-dimensional order parameter was studied in all cases. Chain lengths increased rapidly until saturation at approximately l = 30 μm after a time of about t = 10 s. Similarly, the chain order parameters increased until saturation between S = 0.8-0.9, independent of sample geometry.

Original languageEnglish
Pages (from-to)4636-4643
Number of pages8
JournalSoft Matter
Volume13
Issue number26
Early online date15 Jun 2017
DOIs
Publication statusPublished - 14 Jul 2017

Fingerprint

Nematic liquid crystals
liquid crystals
Magnetic fields
Nanoparticles
nanoparticles
Chain length
Substrates
magnetic fields
Defects
Geometry
Dispersions
Saturn rings
saturation
defects
Boundary conditions
Satellites
geometry
periodic variations
boundary conditions
configurations

Keywords

  • magnetic nanoparticles
  • liquid crystal
  • boundary condition geometries
  • particle chaining

Cite this

Dierking, I. ; Heberle, M. ; Osipov, M. A. ; Giesselmann, F. / Ordering of ferromagnetic nanoparticles in nematic liquid crystals. In: Soft Matter. 2017 ; Vol. 13, No. 26. pp. 4636-4643.
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Dierking, I, Heberle, M, Osipov, MA & Giesselmann, F 2017, 'Ordering of ferromagnetic nanoparticles in nematic liquid crystals', Soft Matter, vol. 13, no. 26, pp. 4636-4643. https://doi.org/10.1039/C7SM01029J

Ordering of ferromagnetic nanoparticles in nematic liquid crystals. / Dierking, I.; Heberle, M.; Osipov, M. A.; Giesselmann, F.

In: Soft Matter, Vol. 13, No. 26, 14.07.2017, p. 4636-4643.

Research output: Contribution to journalArticle

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